Hmmm…. Well I’ll give my experience. I started on the V500…..no lack at power at all. When you lay into her, after getting comfortable with her, she will hit triple digits easily and quickly. The VStar 650 will likely so the same. After several thousand miles on her I stepped up to my V900. Yes both Vulcans. For me I couldn’t deal with the sway back look of the VStars. I absolutely love my 9. More power then I will ever need and enough bolt ons and creature comforts to keep my interest in her for a looong time. Another perk is that here in the states anything under 1000 cc’s keeps the insurance low. Before you discount power and umph for your progression look to see what can be done. For my 900 I can add things like a Big Sucker Ram intake kit, power commander etc. To squeeze more power out of her.
The 1100 IMO would be a huge jump for a first. Weight, power, and not to mention expensive fix should you end up dropping her in the early stages.
I would definitely push you to the 650. Again, if your fear of losing interest is one thing shying you away. Check Vstar forums and look at what other riders are doing for enhancements for down the road improvements. After you get some experience under your belt. Then Once you out gorw that the Star’s usually do really good at retaining most of their value and you can get alot of it back so you can step up to that 1100.